End cover assembly, energy storage apparatus and electric device

Abstract

Provided in the present application are an end cover assembly, an energy storage apparatus and an electric device, which can improve the sealing performance of the end cover assembly to prevent an electrolyte from entering a gap between a cover body and a welding ring, thereby facilitating improvement to the safety and reliability of the energy storage apparatus. The end cover assembly comprises a lower plastic part, a cover body, a terminal, a sealing ring and a welding ring, wherein the cover body is mounted on one side of the lower plastic part in the direction of thickness of the lower plastic part, and in the direction of thickness of the end cover assembly, a boss of the cover body is spaced apart from and arranged opposite the lower plastic part; the terminal passes through a through hole of the lower plastic part and an assembly hole of the cover body; the welding ring is located on the side of the lower plastic part facing away from the cover body and is sleeved on the terminal; and the sealing ring is sleeved on the terminal, and comprises a sealing body and a sealing flange, the sealing body being sleeved on the terminal and clamped between the bottom wall surface of an assembly groove of the cover body and the surface of the welding ring facing the cover body, and the sealing flange being connected to the side of the sealing body facing away from the terminal, arranged around the periphery of the sealing body, and clamped between the boss and the lower plastic part.

Description

End cover assembly, energy storage device and electric equipment

[0001] The present application claims priority to the Chinese patent application No. 202411088362.0, filed on August 08, 2024, entitled "End cover assembly, energy storage device and electric equipment", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of energy storage, in particular to an end cover assembly, an energy storage device and an electric equipment. BACKGROUND

[0003] The rechargeable battery, also known as secondary battery or storage battery, refers to a battery that can be activated by charging after discharging. The recyclable feature of the secondary battery makes it gradually become the main power source of electric equipment. With the increasing demand for secondary batteries, people's requirements for the energy density and use reliability of secondary batteries are also increasing. However, the existing end cover assembly of the secondary battery has poor sealing performance, which leads to the electrolyte easily penetrating into the gap between the cover body and the welding ring, thereby reducing the safety and reliability of the secondary battery. SUMMARY

[0004] The present application provides an end cover assembly, an energy storage device and an electric equipment, which can improve the sealing performance of the end cover assembly, avoid the electrolyte entering the gap between the cover body and the welding ring, and thus help to improve the safety and reliability of the energy storage device.

[0005] In a first aspect, the present application provides an end cover assembly used in an energy storage device. The end cover assembly comprises a lower plastic, a cover body, a pole, a sealing ring and a welding ring. The lower plastic is provided with a through hole penetrating the lower plastic along the thickness direction of the lower plastic. The cover body is mounted on one side of the lower plastic along the thickness direction of the lower plastic. The cover body is provided with an assembly hole penetrating the cover body along the thickness direction of the cover body and communicating with the through hole, and an assembly groove with an opening on the surface of the cover body facing the lower plastic. The assembly groove surrounds the assembly hole and communicates with the assembly hole. The cover body is further provided with a convex block arranged on the groove bottom wall surface of the assembly groove and spaced apart from and opposite to the lower plastic along the thickness direction of the end cover assembly. The pole is arranged in the through hole and the assembly hole. The welding ring is arranged on the side of the lower plastic away from the cover body and surrounds the pole. The sealing ring surrounds the pole and comprises a sealing main body and a sealing flange. The sealing main body surrounds the pole and is clamped between the groove bottom wall surface of the assembly groove and the surface of the welding ring facing the cover body. The sealing flange is connected to the side of the sealing main body away from the pole and surrounds the peripheral side of the sealing main body and is clamped between the convex block and the lower plastic.

[0006] In a second aspect, the present application further provides an energy storage device comprising a shell and the end cover assembly according to any one of the above aspects. The end cover assembly is mounted on the shell and seals the opening of the shell.

[0007] In a third aspect, the present application further provides an electric device comprising the energy storage device according to the above aspect. The energy storage device supplies power to the electric device.

[0008] In the end cover assembly provided by the present application, the sealing flange of the sealing ring is clamped between the cover body and the lower plastic, and the sealing main body is clamped between the cover body and the welding ring. When the sealing flange is compressed, the sealing flange can realize sealing between the cover body and the lower plastic, and sealing between the cover body and the welding ring. This is beneficial to improve the sealing performance of the end cover assembly, so as to prevent the electrolyte in the energy storage device from penetrating from the cover body into the space between the cover body and the welding ring, thereby avoiding short circuit breakdown of the energy storage device in short circuit and voltage test, preventing the energy storage device from catching fire and exploding, and further improving the safety and reliability of the energy storage device. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required by the embodiments of the present application will be described below.

[0010] FIG. 1 is a structural schematic view of an energy storage device provided by the embodiments of the present application;

[0011] Fig. 2 is a structural schematic diagram of an end cover assembly in the energy storage device shown in Fig. 1;

[0012] Fig. 3 is an exploded structural schematic diagram of the end cover assembly shown in Fig. 2;

[0013] Fig. 4 is a sectional structural schematic diagram of the end cover assembly shown in Fig. 2 along A-A;

[0014] Fig. 5 is a structural schematic diagram of a lower plastic in the end cover assembly shown in Fig. 3;

[0015] Fig. 6 is a structural schematic diagram of the lower plastic shown in Fig. 5 along B-B;

[0016] Fig. 7 is a structural schematic diagram of a cover body and an explosion-proof valve in the end cover assembly shown in Fig. 3;

[0017] Fig. 8 is a sectional structural schematic diagram of the cover body shown in Fig. 7 along C-C;

[0018] Fig. 9 is an exploded structural schematic diagram of a first pole column unit in the end cover assembly shown in Fig. 3;

[0019] Fig. 10 is a sectional structural schematic diagram of a first upper plastic in the first pole column unit shown in Fig. 9 along D-D;

[0020] Fig. 11 is a sectional structural schematic diagram of a first pole column in the first pole column unit shown in Fig. 9 along E-E;

[0021] Fig. 12 is a sectional structural schematic diagram of a first welding ring in the first pole column unit shown in Fig. 9 along F-F;

[0022] Fig. 13 is a sectional structural schematic diagram of a first sealing ring in the first pole column unit shown in Fig. 9 along G-G;

[0023] Fig. 14 is an exploded structural schematic diagram of a second pole column unit in the end cover assembly shown in Fig. 3;

[0024] Fig. 15 is a structural schematic diagram of a second upper plastic in the second pole column unit shown in Fig. 14 along H-H;

[0025] Fig. 16 is a structural schematic diagram of a second pole column in the second pole column unit shown in Fig. 14 along I-I;

[0026] Fig. 17 is a structural schematic diagram of a second welding ring in the second pole column unit shown in Fig. 14 along J-J;

[0027] Fig. 18 is a structural schematic diagram of a second sealing ring in the second pole column unit shown in Fig. 14 along K-K.

[0028] Corresponding names of various reference signs in the figure are: energy storage device 100, shell 110, end cover assembly 120, lower plastic 10, cover 20, explosion-proof valve 30, first pole column unit 40, second pole column unit 50, first surface 10a, second surface 10b, explosion-proof fence 101, liquid inlet hole 102, first through hole 103, second through hole 104, first protrusion 11, second protrusion 12, first guide block 13, second guide block 14, first guide surface 131, first end 131a, second end 131b, second guide surface 141, first surface 20a, second surface 20b, explosion-proof hole 201, liquid injection hole 202, first assembly hole 203, second assembly hole 204, mounting groove 205, first assembly groove 206, second assembly groove 207, first protruding block 21, second protruding block 22, protective sheet 60, first upper plastic 41, first pole column 42, first sealing ring 43, first welding ring 44, first mounting hole 411, first matching groove 412, first main body part 413, first extension part 414, protruding part 415, first matching surface 401, first connecting surface 402, first side 402a, second side 402b, first flange part 421, first mounting part 422, first fixing part 423, first assembly part 423a, first matching part 423b, first welding ring main body 441, first blocking ring 442, first matching hole 443, first avoidance notch 444, first side wall surface 444a, first sealing main body 431, first sealing flange 432, first protruding tooth 433, first central surface 43a, second upper plastic 51, second pole column 52, second sealing ring 53, second welding ring 54, second mounting hole 511, second matching groove 512, second main body part 513, second extension part 514, second matching surface 501, second connecting surface 502, second flange part 521, second fixing part 523, second assembly part 523a, second matching part 523b, second welding ring main body 541, second blocking ring 542, second matching hole 543, second avoidance notch 544, second side wall surface 544a, second sealing main body 531, second sealing flange 532, second protruding tooth 533, second central surface 53a, top sheet 70, first avoidance hole 701, second avoidance hole 702, third avoidance hole 703. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application.

[0030] Please refer to FIG. 1, which is a structural schematic diagram of an energy storage device 100 provided by the embodiments of the present application. In order to facilitate description, the length direction of the energy storage device 100 is defined as the X-axis direction, the width direction of the energy storage device 100 is defined as the Y-axis direction, and the height direction of the energy storage device 100 is defined as the Z-axis direction, and the X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.

[0031] The energy storage device 100 includes a housing 110, a winding core (not shown in the figure), and a cover assembly 120. The housing 110 has an opening (not shown in the figure) and a receiving cavity (not shown in the figure), and the opening communicates with the receiving cavity. The winding core is received in the receiving cavity. The receiving cavity is also used to receive an electrolyte, and the winding core is soaked in the electrolyte. The cover assembly 120 is installed on the housing 110 and seals the opening of the housing 110. Exemplarily, the energy storage device 100 is a square battery. In some other embodiments, the energy storage device 100 can also be a cylindrical battery or other batteries.

[0032] Please refer to FIG. 2 to FIG. 4, FIG. 2 is a structural schematic diagram of the cover assembly 120 in the energy storage device 100 shown in FIG. 1, FIG. 3 is an exploded structural schematic diagram of the cover assembly 120 shown in FIG. 2, and FIG. 4 is a sectional structural schematic diagram of the cover assembly 120 shown in FIG. 2 along A-A. Wherein, “along A-A” means that the cover assembly 120 is cut along the plane where the line A-A is located, and similar descriptions hereinafter can be understood in the same way.

[0033] The cover assembly 120 includes a lower plastic 10, a cover body 20, an explosion-proof valve 30, a first pole unit 40, and a second pole unit 50. The lower plastic 10 is installed on one side of the cover body 20 in the thickness direction. The explosion-proof valve 30, the first pole unit 40, and the second pole unit 50 are all installed on the cover body 20. Wherein, along the length direction of the energy storage device 100, the first pole unit 40 and the second pole unit 50 are respectively located on the opposite sides of the explosion-proof valve 30.

[0034] Please refer to FIG. 4, FIG. 5, and FIG. 6 in combination, FIG. 5 is a structural schematic diagram of the lower plastic 10 in the cover assembly 120 shown in FIG. 3, and FIG. 6 is a structural schematic diagram of the lower plastic 10 shown in FIG. 5 along B-B.

[0035] The lower plastic 10 includes a first surface 10a and a second surface 10b, and the first surface 10a and the second surface 10b are oppositely arranged in the thickness direction of the lower plastic 10. Wherein, the first surface 10a is the surface of the lower plastic 10 away from the housing 110, and the second surface 10b is the surface of the lower plastic 10 toward the housing 110. The lower plastic 10 further includes an explosion-proof fence 101, and the explosion-proof fence 101 penetrates the first surface 10a and the second surface 10b of the lower plastic 10. Specifically, the explosion-proof fence 101 is located in the middle of the lower plastic 10.

[0036] In the embodiment, the lower plastic 10 is further provided with a liquid inlet hole 102, a first through hole 103 and a second through hole 104. The liquid inlet hole 102, the first through hole 103 and the second through hole 104 all penetrate the first surface 10a and the second surface 10b of the lower plastic 10 along the thickness direction (the Z-axis direction shown in the figure) of the lower plastic 10 and are arranged at intervals from each other. Specifically, along the length direction (the X-axis direction shown in the figure) of the energy storage device 100, the liquid inlet hole 102 is located at the middle of the lower plastic 10 and is arranged at an interval from the explosion-proof fence 101 on one side of the explosion-proof fence 101.

[0037] Along the length direction (the X-axis direction shown in the figure) of the energy storage device 100, the first through hole 103 and the second through hole 104 are both located at the edge of the lower plastic 10 and are arranged at intervals from the liquid inlet hole 102 and the explosion-proof fence 101. In the embodiment, specifically, the first through hole 103 is located on the side of the liquid inlet hole 102 away from the explosion-proof fence 101, and the second through hole 104 is located on the side of the explosion-proof fence 101 away from the liquid inlet hole 102.

[0038] In the embodiment, the lower plastic 10 is further provided with a first protrusion 11 and a second protrusion 12. The first protrusion 11 is fixedly connected to the hole wall of the first through hole 103. The second protrusion 12 is fixedly connected to the hole wall of the second through hole 104. Along the length direction (the X-axis direction shown in the figure) of the lower plastic 10, the second protrusion 12 is arranged at an interval from the first protrusion 11. Exemplarily, the first protrusion 11 and the second protrusion 12 are both annular.

[0039] In addition, the lower plastic 10 is further provided with a first guide block 13 and a second guide block 14. Specifically, the first surface 10a is provided with the first guide block 13 and the second guide block 14. The first guide block 13 is arranged around the periphery of the first through hole 103. Exemplarily, the first guide block 13 has a plurality of first guide blocks 13. The plurality of first guide blocks 13 are arranged at intervals around the first protrusion 11. Each first guide block 13 comprises a first guide surface 131. The first guide surface 131 is located on the side of the first guide block 13 away from the first through hole 103. Specifically, the first guide surface 131 comprises a first end 131a close to the first surface 10a and a second end 131b arranged away from the first end 131a. From the first end 131a to the second end 131b, the distance between the first guide surface 131 and the first surface 10a of the lower plastic 10 gradually increases.

[0040] The second guide block 14 is fixedly connected to the side of the second protrusion 12 away from the second through hole 104. In this embodiment, the structure of the second guide block 14 is the same as that of the first guide block 13 described above. For example, the second guide block 14 can have a plurality of second guide blocks 14. The plurality of second guide blocks 14 are arranged at intervals around the periphery of the second protrusion 12. Each second guide block 14 includes a second guide surface 141. The structure of the second guide surface 141 and the positional relationship of the second guide surface 141 in the second guide block 14 can be referred to the related description of the structure of the first guide surface 131 and the positional relationship of the first guide surface 131 in the first guide block 13, which will not be repeated here.

[0041] Please refer to FIG. 4, FIG. 7 and FIG. 8, FIG. 7 is a structural schematic diagram of the cover body 20 and the explosion-proof valve 30 in the end cover assembly 120 shown in FIG. 3, and FIG. 8 is a sectional structural schematic diagram of the cover body 20 shown in FIG. 7 along C-C.

[0042] The cover body 20 includes a first surface 20a and a second surface 20b. The first surface 20a and the second surface 20b are arranged opposite to each other along the thickness direction (the direction of the Z axis shown in the figure) of the cover body 20. The first surface 20a is the side of the cover body 20 away from the lower plastic 10, and the second surface 20b is the side of the cover body 20 toward the lower plastic 10.

[0043] The cover body 20 is also provided with an explosion-proof hole 201, a liquid injection hole 202, a first assembly hole 203, a second assembly hole 204, a mounting groove 205, a first assembly groove 206 and a second assembly groove 207. The explosion-proof hole 201, the liquid injection hole 202, the first assembly hole 203 and the second assembly hole 204 all penetrate the first surface 20a and the second surface 20b of the cover body 20 along the thickness direction (the direction of the Z axis shown in the figure) of the cover body 20, and are arranged at intervals.

[0044] Specifically, the explosion-proof hole 201 and the liquid injection hole 202 are both located in the middle of the cover body 20. The explosion-proof hole 201 can be connected to the inside of the energy storage device 100 through the explosion-proof fence 101. Along the length direction of the cover body 20, the liquid injection hole 202 is located on one side of the explosion-proof hole 201. The liquid injection hole 202 is in communication with the liquid inlet hole 102 of the lower plastic 10. The electrolyte can be injected into the accommodation cavity of the shell 110 (as shown in FIG. 1) through the liquid injection hole 202 of the cover body 20 and the liquid inlet hole 102 of the lower plastic 10 in sequence, so as to realize the perfusion of the electrolyte of the energy storage device 100.

[0045] The first assembly hole 203 and the second assembly hole 204 are both located at the edge of the cover 20 along the length direction (X-axis direction in the figure) of the energy storage device 100, and are respectively located at opposite sides of the explosion-proof hole 201 and the liquid injection hole 202. Specifically, the first assembly hole 203 is located at the side of the liquid injection hole 202 away from the explosion-proof hole 201. The second assembly hole 204 is located at the side of the explosion-proof hole 201 away from the liquid injection hole 202. The first assembly hole 203 is in communication with the first through hole 103 of the lower plastic 10 to facilitate installation of the first pole unit 40. The second assembly hole 204 is in communication with the second through hole 104 of the lower plastic 10 to facilitate installation of the second pole unit 50.

[0046] The opening of the mounting groove 205 is located at the first surface 20a of the cover 20. The mounting groove 205 is recessed from the first surface 20a to the second surface 20b. The mounting groove 205 is arranged around the periphery of the first assembly hole 203 and is spaced apart from the first assembly hole 203. In other embodiments, when the liquid injection hole 202 is arranged between the explosion-proof hole 201 and the second assembly hole 204, i.e., the second assembly hole 204 is arranged close to the liquid injection hole 202, the mounting groove 205 can also be arranged around the periphery of the second assembly hole 204 and be spaced apart from the second assembly hole 204.

[0047] In this embodiment, the opening of the first assembly groove 206 and the opening of the second assembly groove 207 are both located at the second surface 20b of the cover 20. The first assembly groove 206 is recessed from the second surface 20b to the first surface 20a and penetrates the hole wall surface of the first assembly hole 203. The first assembly groove 206 is arranged around the first assembly hole 203 and is in communication with the first assembly hole 203.

[0048] The second assembly groove 207 is recessed from the second surface 20b to the first surface 20a and penetrates the hole wall surface of the second assembly hole 204. The second assembly groove 207 is arranged around the second assembly hole 204 and is in communication with the second assembly hole 204. Along the length direction of the cover plate, the second assembly groove 207 is spaced apart from the first assembly groove 206.

[0049] In the assembling process of the cover 20 and the lower plastic 10, since the first guide surface 131 of the first guide block 13 and the second guide surface 141 of the second guide block 14 are both inclinedly arranged, the first guide surface 131 and the second guide surface 141 can guide and position the installation of the lower plastic 10. Specifically, the first guide block 13 is installed into the first assembling groove 206 so that the first through hole 103 is aligned with and communicated with the first assembling hole 203. The second guide block 14 is installed into the second assembling groove 207 so that the second through hole 104 of the lower plastic 10 is aligned with and communicated with the second assembling hole 204. With this arrangement, the lower plastic 10 can be prevented from being deviated during the assembling process of the lower plastic 10 and the cover 20, so that the lower plastic 10 and the cover 20 can be accurately aligned, thereby ensuring that the first pole unit 40 and the second pole unit 50 can be accurately assembled with the cover 20 and the lower plastic 10, and the end cover assembly 120 can be prevented from being assembled improperly.

[0050] In addition, the side of the cover 20 facing the lower plastic 10 is further provided with a first protruding block 21 and a second protruding block 22. Specifically, the first protruding block 21 is arranged on the bottom wall surface of the first assembling groove 206 and surrounds the periphery of the first assembling hole 203. For example, the first protruding block 21 is substantially annular. In the thickness direction of the end cover assembly 120, the first protruding block 21 is spaced apart from and opposite to the first protruding block 11 of the lower plastic 10. The second protruding block 22 is arranged on the bottom wall surface of the second assembling groove 207 and surrounds the periphery of the second assembling hole 204. For example, the second protruding block 22 is substantially annular. In the thickness direction of the end cover assembly 120, the second protruding block 22 is spaced apart from and opposite to the first protruding block 11 of the lower plastic 10.

[0051] It can be understood that, by arranging the first protruding block 21 and the second protruding block 22 on the side of the cover 20 facing the lower plastic 10, the thickness of the cover 20 can be increased, thereby enhancing the structural strength of the cover 20, and further helping to improve the use reliability of the cover 20 and prolong the service life of the cover 20.

[0052] Please refer to FIG. 4 and FIG. 7. The explosion-proof valve 30 is installed in the explosion-proof hole 201 and fixedly connected to the hole wall of the explosion-proof hole 201. For example, the explosion-proof valve 30 can be fixedly connected to the hole wall of the explosion-proof hole 201 by welding to be installed in the explosion-proof hole 201. It can be understood that, since the explosion-proof hole 201 communicates the inside and the outside of the energy storage device 100, when the air pressure inside the energy storage device 100 is too large, the explosion-proof valve 30 will be broken under the action of the air pressure, and the gas inside the energy storage device 100 can be discharged to the outside of the energy storage device 100 in time through the explosion-proof fence 101 of the lower plastic 10 and the explosion-proof hole 201, thereby avoiding the explosion of the energy storage device 100 and improving the use reliability of the energy storage device 100.

[0053] In the embodiment, the end cover assembly 120 can further include a protective sheet 60. The protective sheet 60 is mounted to the cover plate and covers the explosion-proof hole 201. The protective sheet 60 is used to protect the explosion-proof valve 30 from damage caused by external environment and external force, thereby preventing the explosion-proof valve 30 from being accidentally touched and ensuring good use reliability of the energy storage device 100.

[0054] Please refer to FIG. 4, FIG. 9 and FIG. 10, FIG. 9 is an exploded structural schematic view of the first pole unit 40 in the end cover assembly 120 shown in FIG. 3, and FIG. 10 is a sectional structural schematic view of the first upper plastic 41 in the first pole unit 40 shown in FIG. 9 along the D-D section.

[0055] The first pole unit 40 includes the first upper plastic 41, the first pole 42, the first sealing ring 43 and the first welding ring 44, and the first upper plastic 41, the first sealing ring 43 and the first welding ring 44 are all sleeved on the first pole 42. The first upper plastic 41 is mounted to the cover body 20 and located between the cover body 20 and the first pole 42. Specifically, the first upper plastic 41 is provided with a first mounting hole 411 and a first matching groove 412. The first mounting hole 411 penetrates the first upper plastic 41 along the thickness direction of the first upper plastic 41 and coaxially and communicatively connected to the first assembly hole 203 of the cover body 20. The opening of the first matching groove 412 is located on the surface of the first upper plastic 41 away from the cover body 20. The first matching groove 412 is recessed from the surface of the first upper plastic 41 away from the cover body 20 to the cover body 20 and penetrates the hole wall of the first mounting hole 411 and is in communication with the first mounting hole 411.

[0056] The first upper plastic 41 further includes a first main body 413, a first extension 414 and a protruding part 415, and the first extension 414 and the protruding part 415 are fixedly connected to the first main body 413. The first main body 413 is sleeved on the first pole 42 and located between the first pole 42 and the cover body 20. The first main body 413 is provided with the first matching groove 412 and the first mounting hole 411. The opening of the first matching groove 412 is located on the surface of the first main body 413 away from the cover body 20.

[0057] The first main body part 413 further comprises a first matching surface 401 and a first connecting surface 402 facing away from the cover body 20. The opening of the first matching groove 412 is located on the first matching surface 401. The first matching surface 401 is a plane in an example, so as to facilitate the abutment of the first matching surface 401 and the first pole column 42. The first connecting surface 402 is fixedly connected to the first matching surface 401 and is arranged around the circumferential side of the first matching surface 401. The first connecting surface 402 is an arc surface in an example. The first connecting surface 402 comprises a first side 402a close to the first pole column 42 and a second side 402b arranged opposite to the first side 402a. The distance between the first connecting surface 402 and the first surface 20a of the cover body 20 gradually decreases in the direction from the first side 402a to the second side 402b. That is, the first connecting surface 402 is an inclined arc surface.

[0058] It can be understood that when the injection nozzle is separated from the injection hole 202 after the energy storage device 100 is finished with liquid injection, the electrolyte is easy to splash to the surface of the first upper plastic 41. By arranging the first connecting surface 402 on the first upper plastic 41 and making the first connecting surface 402 be inclined, the electrolyte is not easy to remain on the first connecting surface 402, so that the crystallization of electrolyte on the surface of the first upper plastic 41 can be avoided, thereby helping to keep the appearance of the end cover assembly 120 clean and reducing the appearance defect rate of the energy storage device 100. At the same time, the first connecting surface 402 arranged in an inclined arc shape has a large area, so that even if the electrolyte remains on the first connecting surface 402, it is easy to be wiped, thereby also helping to prevent the crystallization of electrolyte on the first connecting surface 402, and further helping to keep the appearance of the end cover assembly 120 clean and reducing the appearance defect rate of the energy storage device 100.

[0059] In the embodiment, the first extension part 414 and the protruding part 415 are both fixedly connected to the side of the first main body part 413 facing the cover body 20. The first extension part 414 is arranged around the circumferential side of the first mounting hole 411. Specifically, the first extension part 414 is mounted in the first assembly hole 203 of the cover body 20.

[0060] The protruding part 415 is mounted in the mounting groove 205 of the cover body 20. This arrangement can improve the assembly reliability between the first upper plastic 41 and the cover body 20. In the embodiment, the protruding part 415 is arranged in a spaced manner around the circumferential side of the first extension part 414, and the outer circumferential surface of the protruding part 415 protrudes relative to the outer circumferential surface of the first main body part 413. With this arrangement, the assembly gap between the first upper plastic 41 and the cover body 20 can be extended, so that the electrolyte remaining on the surface of the first upper plastic 41 can be prevented from directly flowing into the assembly gap between the first upper plastic 41 and the cover body 20, thereby being able to reduce the amount of electrolyte flowing into the assembly gap between the first upper plastic 41 and the cover body 20 to a certain extent and reducing the possibility of the crystallization of electrolyte in the assembly gap between the first upper plastic 41 and the cover body 20.

[0061] Please refer to FIG. 9 and FIG. 11, FIG. 11 is a sectional structure schematic diagram of the first pole 42 in the first pole unit 40 shown in FIG. 9 along E-E.

[0062] The first pole 42 penetrates the first mounting hole 411 of the first upper plastic 41, the first assembly hole 203 of the cover 20 and the first through hole 103 of the lower plastic 10. For example, the first pole 42 is a positive pole, and is made of aluminum material. In other embodiments, the first pole 42 can also be a negative pole, and the embodiments of the present application do not make strict limitations on this.

[0063] In the embodiment, the first pole 42 includes a first flange part 421, a first mounting part 422 and a first fixing part 423, and the first mounting part 422 and the first fixing part 423 are located on one side of the thickness direction of the first flange part 421. Specifically, the first mounting part 422 is fixedly connected to the first flange part 421. Among them, the peripheral side surface of the first flange part 421 protrudes relative to the peripheral side surface of the first mounting part 422. The first fixing part 423 is fixedly connected to one side of the first mounting part 422 away from the first flange part 421. Specifically, the first fixing part 423 includes a first assembly part 423a and a first matching part 423b. The first matching part 423b is connected to one side of the first assembly part 423a, and the peripheral side surface of the first matching part 423b is flush with the peripheral side surface of the first assembly part 423a.

[0064] Specifically, the first flange part 421 of the first pole 42 is located on one side of the first main body part 413 of the first upper plastic 41 away from the cover 20. Among them, the surface of the first flange part 421 towards the first main body part 413 abuts against the first matching surface 401. The peripheral side surface of the first flange part 421 is spaced apart from the first connecting surface 402. Specifically, the first side 402a of the first connecting surface 402 is spaced apart from the peripheral side surface of the first flange part 421. Under this setting, after the first pole 42 and the first upper plastic 41 are assembled, on the one hand, the first side 402a is spaced apart from the peripheral side surface of the first flange part 421, and the first connecting surface 402 will not enter the assembly gap between the first pole 42 and the first upper plastic 41, which facilitates wiping the electrolyte remaining on the first connecting surface 402, on the other hand, the assembly gap between the first flange part 421 and the first main body part 413 of the first pole 42 is arranged in a horizontal direction, which prevents the electrolyte from entering the assembly gap between the first main body part 413 and the first flange part 421, thereby reducing the possibility of subsequent crystallization of the electrolyte, which in turn helps to reduce the appearance defect rate of the energy storage device 100 and ensure the appearance neatness of the energy storage device 100.

[0065] The first mounting portion 422 of the first pole column 42 is mounted in the first matching groove 412 of the first upper plastic 41. The first fixing portion 423 penetrates the first mounting hole 411 of the first upper plastic 41, the first assembly hole 203 of the cover body 20, and the first through hole 103 of the lower plastic 10. Specifically, the first assembly portion 423a of the first fixing portion 423 penetrates the first mounting hole 411 and the first assembly hole 203, and the first matching portion 423b of the first fixing portion 423 penetrates the first through hole 103. One part of the first main body portion 413 is located between the first flange portion 421 and the cover body 20, and the other part of the first main body portion 413 is located between the first mounting portion 422 and the cover body 20. The first extension portion 414 of the first upper plastic 41 is located between the circumferential side surface of the first fixing portion 423 of the first pole column 42 and the hole wall surface of the first assembly hole 203. With this arrangement, the short circuit problem of the end cover assembly 120 caused by the direct contact between the first pole column 42 and the cover body 20 can be avoided.

[0066] Please refer to FIGS. 4, 9 and 12. FIG. 12 is a sectional view of the first welding ring 44 of the first pole column unit 40 along F-F in FIG. 9.

[0067] In this embodiment, the first welding ring 44 is located on the side of the cover body 20 away from the first upper plastic 41 and is sleeved on the first pole column 42. Specifically, the first welding ring 44 is mounted in the first through hole 103 of the lower plastic 10, abuts against the first protrusion 11, and is welded and fixed with the first pole column 42. Specifically, the first welding ring 44 includes a first welding ring main body 441 and a first blocking ring 442, and the first blocking ring 442 is fixedly connected to the first welding ring main body 441. The first welding ring main body 441 is provided with a first matching hole 443. The first matching hole 443 penetrates the first welding ring main body 441 in the thickness direction of the first welding ring main body 441. The first blocking ring 442 is located in the first matching hole 443 and is fixedly connected to the hole wall surface of the first matching hole 443. The thickness of the first blocking ring 442 is between 0.2 mm and 0.5 mm. The difference between the inner diameter d1 of the first blocking ring 442 and the hole diameter D1 of the first matching hole 443 is between 0.3 mm and 1 mm.

[0068] Specifically, the first welding ring main body 441 is sleeved on the first matching portion 423b of the first fixing portion 423 of the first pole column 42. That is, the first matching portion 423b penetrates the first matching hole 443. In the thickness direction of the end cover assembly 120, the first blocking ring 442 is located on the side of the first matching portion 423b away from the first assembly portion 423a and blocks the gap between the first matching portion 423b and the first welding ring main body 441. When the first welding ring 44 is welded with the first pole column 42, the first blocking ring 442 melts and fills the gap between the first welding ring main body 441 and the first matching portion 423b of the first pole column 42.

[0069] In the embodiment, the first blocking ring 442 is arranged on the first welding ring 44, and the first blocking ring 442 blocks the assembly gap between the first assembly portion 423a and the first welding ring body 441. When the first welding ring 44 and the first pole column 42 are laser welded, the first blocking ring 442 is first melted by laser, and fills the assembly gap between the first assembly portion 423a and the first welding ring body 441, so that the laser is blocked from entering the assembly gap between the first assembly portion 423a and the first welding ring body 441, and the welding burst problem caused by the first upper plastic 41 being burned is avoided, thereby helping to reduce the welding failure rate between the first pole column 42 and the first welding ring 44. At the same time, the peripheral side surface of the first assembly portion 423a is flush with the peripheral side surface of the first assembly portion 423b, so that the fitting position of the first welding ring body 441 and the first pole column 42 has no step structure, and interference fit between the first welding ring body 441 and the first pole column 42 is avoided, so that the first welding ring 44 and the first pole column 42 can be prevented from forming a false sealing state, so as to avoid that the product with abnormal sealing state cannot be detected when the energy storage device 100 is subjected to short circuit and withstand voltage test, thereby avoiding the unqualified products from flowing out, and helping to improve the production quality of the energy storage device 100.

[0070] In the embodiment, the first welding ring 44 further comprises a first avoiding gap 444. Specifically, the opening of the first avoiding gap 444 is located on the surface of the first welding ring body 441 of the first welding ring 44 facing the cover 20. The first avoiding gap 444 is recessed from the surface of the first welding ring body 441 facing the cover 20 to the direction away from the cover 20, and penetrates the peripheral side surface of the first welding ring body 441 of the first welding ring 44. The first avoiding gap 444 is arranged around the first fitting hole 443 and is spaced apart from the first fitting hole 443. The first avoiding gap 444 avoids the first protrusion 11 of the lower plastic 10. With the above arrangement, on the one hand, the first protrusion 11 can be given space in the thickness direction of the end cover assembly 120, so as to prevent the first protrusion 11 from being broken due to being too thin when the first welding ring 44 and the first pole column 42 are crimped, so as to prevent the electrolyte in the energy storage device 100 from penetrating into the first welding ring 44 and the cover 20 through the gap between the first welding ring 44 and the first protrusion 11 of the lower plastic 10, improve the insulation performance between the first welding ring 44 and the cover 20, avoid short circuit problem in the end cover assembly 120, and help to improve the assembly reliability of the first welding ring 44 and the lower plastic 10, and improve the assembly reliability of the end cover assembly 120. On the other hand, the area of the crimping surface between the first welding ring 44 and the lower plastic 10 can be increased, so as to prolong the penetration path of the electrolyte, and further improve the sealing performance of the end cover assembly 120.

[0071] In addition, the first avoiding gap 444 comprises a first side wall surface 444a. The first side wall surface 444a is arranged around the circumferential side of the first pole post 42. Specifically, the first side wall surface 444a is arranged around the circumferential side of the first fixed part 423 of the first pole post 42. In the embodiment, the first side wall surface 444a is located between the surface of the first protruding block 21 of the cover 20 facing the first pole post 42 and the circumferential side surface of the first pole post 42. Specifically, the first side wall surface 444a is located between the surface of the first protruding block 21 facing the first fixed part 423 and the circumferential side surface of the first fixed part 423. With the arrangement, the first side wall surface 444a can be arranged in a staggered manner with the surface of the first protruding block 21 facing the first pole post 42.

[0072] Please refer to FIG. 4, FIG. 9 and FIG. 13. FIG. 13 is a sectional structure schematic diagram of the first sealing ring 43 in the first pole post unit 40 along G-G in FIG. 9.

[0073] The first sealing ring 43 is sleeved on the first fixed part 423 of the first pole post 42 and clamped between the cover 20 and the lower plastic 10 and between the cover 20 and the first welding ring 44. The first sealing ring 43 can not only ensure the assembly stability between the first welding ring 44 and the cover 20 and between the lower plastic 10 and the cover 20, but also can avoid the direct contact and conduction between the first welding ring 44 and the cover 20, thereby realizing the insulation between the first welding ring 44 and the cover 20.

[0074] Specifically, the first sealing ring 43 comprises a first sealing body 431, a first sealing flange 432 and a first protruding tooth 433. The first sealing flange 432 and the first protruding tooth 433 are fixedly connected to the first sealing body 431 and located at opposite sides of the first sealing body 431, respectively. Specifically, the first sealing body 431 is sleeved on the first fixed part 423 of the first pole post 42 and clamped between the groove bottom wall surface of the first assembly groove 206 of the cover 20 and the surface of the first welding ring body 441 of the first welding ring 44 facing the cover 20. The first sealing body 431 seals the gap between the groove bottom wall surface of the first assembly groove 206 and the surface of the first welding ring body 441 of the first welding ring 44 facing the cover 20.

[0075] The first sealing flange 432 is connected to the side of the first sealing body 431 away from the first fixed part 423 of the first pole post 42, arranged around the circumferential side of the first sealing body 431 and clamped between the first protruding block 21 of the cover 20 and the first protruding block 11 of the lower plastic 10. The first sealing flange 432 seals the gap between the first protruding block 11 of the lower plastic 10 and the first protruding block 21 of the cover 20. It can be understood that, by arranging the first side wall surface 444a of the first welding ring 44 in a staggered manner with the surface of the first protruding block 21 facing the first pole post 42, the first sealing flange 432 can be provided with the maximum pressure bonding area, thereby helping to improve the sealing performance between the cover 20 and the lower plastic 10.

[0076] In the embodiment, the thickness of the first sealing flange 432 is less than the thickness of the first sealing body 431 along the thickness direction of the end cover assembly 120, and the compression amount of the first sealing flange 432 is less than the compression amount of the first sealing body 431. In the embodiment, the ratio a1 of the initial thickness of the first sealing flange 432 to the distance between the surface of the lower plastic 10 facing the first protrusion 21 and the surface of the first protrusion 21 facing the lower plastic 10 is 1.08≤a1≤2.22. The ratio b1 of the initial thickness of the first sealing body 431 to the distance between the bottom wall surface of the first assembly groove 206 and the surface of the first welding ring 44 facing the cover 20 is 1.31≤b1≤1.92. The “initial thickness of the first sealing flange 432” refers to the thickness of the first sealing flange 432 before compression, and the “initial thickness of the first sealing body 431” refers to the thickness of the first sealing body 431 before compression. With this arrangement, the compression amount of the first sealing flange 432 can be ensured to be less than the compression amount of the first sealing body 431, thereby preventing the first sealing flange 432 from affecting the overall sealing performance of the end cover assembly 120.

[0077] It should be noted that in actual production, the size and assembly tolerance of the components such as the lower plastic 10 and the cover 20 in the end cover assembly 120 need to be adjusted according to the requirements of the product to control the compression amount of the first sealing flange 432 and the first sealing body 431 of the first sealing ring 43.

[0078] It can be understood that during the assembly of the end cover assembly 120, when the first welding ring 44 is welded with the first pole 42, the first welding ring 44 will extrude the lower plastic 10 and the first sealing ring 43, and the first sealing flange 432 of the first sealing ring 43 will be firmly clamped between the first protrusion 21 of the cover 20 and the first protrusion 11 of the lower plastic 10. The first sealing flange 432 is extruded and compressed, and seals the gap between the first protrusion 21 and the first protrusion 11, thereby achieving the sealing between the cover 20 and the lower plastic 10, preventing the electrolyte inside the energy storage device 100 from entering between the cover 20 and the first welding ring 44 through the gap between the first protrusion 21 of the cover 20 and the first protrusion 11 of the lower plastic 10, thereby avoiding short circuit breakdown of the energy storage device 100 in short circuit and voltage test, preventing the energy storage device 100 from catching fire and explosion, and further improving the safety and reliability of the energy storage device 100.

[0079] The first protrusion 433 is connected to one side of the first assembly part 423a of the first sealing body 431 facing the first pole 42, and abuts against the first assembly part 423a of the first pole 42, so that the peripheral surface of the first assembly part 423a of the first pole 42 is spaced apart from the first sealing body 431. It can be understood that by arranging the first protrusion 433 on the side of the first sealing body 431 of the first sealing ring 43 facing the first pole 42, and abutting against the first pole 42, the first sealing body 431 of the first sealing ring 43 can be spaced apart from the peripheral surface of the first pole 42 during compression of the first sealing ring 43, so as to avoid the false sealing state caused by the first sealing body 431 of the first sealing ring 43 being compressed and adhering to the first pole 42 or the first upper plastic 41, and to solve the problem that the sealing performance of the welding part or other sealing parts of the end cover assembly 120 is not easy to detect when the sealing performance is abnormal, thereby reducing the outflow rate of defective products and improving the production quality of the energy storage device 100.

[0080] In this embodiment, the first protrusion 433 has a plurality of first protrusions 433. The plurality of first protrusions 433 are arranged at intervals around the first pole 42. During compression of the first sealing ring 43, the plurality of first protrusions 433 abut against the first pole 42, which can prevent the first pole 42 from deviating, thereby helping to ensure good use reliability of the end cover assembly 120.

[0081] In this embodiment, the first sealing ring 43 further comprises a first central surface 43a. The first central surface 43a is perpendicular to the thickness direction of the first sealing ring 43, and passes through the first sealing body 431, the first sealing flange 432 and the first protrusion 433. Along the thickness direction of the first sealing ring 43, the first sealing ring 43 is mirror-symmetric about the first central surface 43a. With this arrangement, during assembly of the end cover assembly 120, the front and back positions of the first sealing ring 43 do not need to be considered, thereby helping to reduce the assembly difficulty of the first sealing ring 43 in the end cover assembly 120, and thereby facilitating the acceleration of the production rhythm of the end cover assembly 120 and improving the production efficiency.

[0082] In addition, when the first sealing ring 43 is assembled with the lower plastic 10, the plurality of first guide blocks 13 of the lower plastic 10 are located on the side of the first sealing flange 432 away from the first sealing body 431. With this arrangement, the assembly position of the first sealing ring 43 in the end cover assembly 120 can be limited, and the compression space of the first sealing ring 43 can be ensured when the first sealing ring 43 is compressed.

[0083] Please refer to FIG. 4, FIG. 14 and FIG. 15, FIG. 14 is an exploded structural schematic view of the second pole unit 50 in the end cover assembly 120 shown in FIG. 3, and FIG. 15 is a structural schematic view of the second upper plastic 51 in the second pole unit 50 shown in FIG. 14, along the H-H section.

[0084] The second pole post unit 50 comprises a second upper plastic 51, a second pole post 52, a second sealing ring 53 and a second welding ring 54. The structure of each component in the second pole post unit 50, the assembly relationship between components, and the assembly relationship between components and the lower plastic 10 and the cover 20 can be referred to the relevant description of the first pole post unit 40 above, and will not be repeated here.

[0085] In the embodiment, the structure of the second upper plastic 51 is similar to that of the first upper plastic 41. The difference is that the second upper plastic 51 comprises a second main body part 513 and a second extension part 514. The positional relationship between the second main body part 513 and the second extension part 514 can be referred to the positional relationship between the first main body part 413 and the first extension part 414 in the first upper plastic 41 above. The second upper plastic 51 is also provided with a second mounting hole 511 and a second matching groove 512, and the positional relationship between the second mounting hole 511 and the second matching groove 512 in the second upper plastic 51 can be referred to the relevant description of the first mounting hole 411 and the first matching groove 412 in the first upper plastic 41 above, and will not be repeated here.

[0086] In other embodiments, when the injection hole 202 is arranged between the explosion-proof hole 201 and the second assembly hole 204, i.e. the injection hole 202 is arranged close to the second assembly hole 204, the second upper plastic 51 can also comprise a protruding part 415 (not shown in FIG. 15), and the positional relationship of the protruding part 415 in the second upper plastic 51 can be referred to the relevant description of the positional relationship of the protruding part 415 in the first upper plastic 41 above, and will not be repeated here.

[0087] In the embodiment, the second main body part 513 comprises a second matching surface 501 and a second connecting surface 502 which are away from the cover 20. The position of the second matching surface 501 and the second connecting surface 502 in the second main body part 513, the positional relationship between the second matching surface 501 and the second connecting surface 502, and the positional relationship between the second matching surface 501 and the second connecting surface 502 and the second pole post 52 can be referred to the relevant description of the first matching surface 401 and the first connecting surface 402 above, and will not be repeated here.

[0088] Please refer to FIG. 4, FIG. 14 and FIG. 16, and FIG. 16 is a structure schematic diagram of the second pole post 52 in the second pole post unit 50 shown in FIG. 14 along I-I.

[0089] The second pole post 52 has a structure similar to that of the first pole post 42. The difference is that the second pole post 52 comprises a second flange portion 521 and a second fixed portion 523. The second fixed portion 523 is fixedly connected to one side of the second flange portion 521 in the thickness direction. The peripheral side surface of the second flange portion 521 is protruded relative to the peripheral side surface of the second fixed portion 523. The second fixed portion 523 comprises a second assembly portion 523a and a second matching portion 523b. The second matching portion 523b is connected to one side of the second assembly portion 523a, and the peripheral side surface of the second matching portion 523b is flush with the peripheral side surface of the second assembly portion 523a.

[0090] Specifically, the second flange portion 521 is installed in the second matching groove 512, and the second fixed portion 523 is arranged through the second mounting hole 511 of the second upper plastic 51, the second assembly hole 204 of the cover body 20, and the second through hole 104 of the lower plastic 10. Specifically, the second assembly portion 523a of the second fixed portion 523 is arranged through the second mounting hole 511 and the second assembly hole 204, and the second matching portion 523b of the second fixed portion 523 is arranged through the second through hole 104. The second main body portion 513 of the second upper plastic 51 is located between the second flange portion 521 and the cover body 20, and the second extension portion 514 is located between the peripheral side surface of the second fixed portion 523 of the second pole post 52 and the hole wall surface of the second assembly hole 204. With this arrangement, the short circuit problem of the end cover assembly 120 caused by the direct contact between the second pole post 52 and the cover body 20 can be avoided.

[0091] Please refer to FIG. 4, FIG. 14 and FIG. 17. FIG. 17 is a structure schematic diagram of the second welding ring 54 in the second pole post unit 50 shown in FIG. 14 along the section J-J.

[0092] The second welding ring 54 has the same structure as the first welding ring 44. The second welding ring 54 is located on the side of the cover 20 away from the second upper plastic 51. Specifically, the second welding ring 54 is installed in the second through hole 104 of the lower plastic 10, abuts against the second protrusion 12, and is welded and fixed with the second pole column 52. Specifically, the second welding ring 54 includes a second welding ring body 541 and a second blocking ring 542, and the second blocking ring 542 is fixedly connected to the second welding ring body 541. The second welding ring body 541 is provided with a second matching hole 543. The second matching hole 543 penetrates the second welding ring body 541 along the thickness direction of the second welding ring body 541. The second blocking ring 542 is located in the second matching hole 543 and is fixedly connected to the hole wall surface of the second matching hole 543. The thickness of the second blocking ring 542 is between 0.2mm and 0.5mm. The difference between the inner diameter d2 of the second blocking ring 542 and the hole diameter D2 of the second matching hole 543 is between 0.3mm and 1mm. That is, the width of the second blocking ring 542 is between 0.3mm and 1mm. With this arrangement, the second blocking ring 542 can have a certain thickness and width to shield the gap between the second pole column 52 and the second welding ring body 541.

[0093] Specifically, the second welding ring body 541 is sleeved on the second matching portion 523b of the second fixed portion 523 of the second pole column 52. That is, the second matching portion 523b penetrates the second matching hole 543. Along the thickness direction of the end cover assembly 120, the second blocking ring 542 is located on the side of the second matching portion 523b away from the second assembly portion 523a and shields the gap between the second matching portion 523b and the second welding ring body 541. When the second welding ring 54 is welded with the second pole column 52, the second blocking ring 542 melts and fills the gap between the second welding ring body 541 and the second matching portion 523b of the second pole column 52.

[0094] In the embodiment, the second blocking ring 542 is arranged on the second welding ring 54, and the second blocking ring 542 blocks the assembly gap between the second assembly part 523a and the second welding ring body 541. When the second welding ring 54 and the second pole column 52 are laser welded, the second blocking ring 542 is first melted by laser, and fills the assembly gap between the second assembly part 523a and the second welding ring body 541, so that the laser is blocked from entering the assembly gap between the second assembly part 523a and the second welding ring body 541, and the welding burst problem caused by the second upper plastic 51 being burned is avoided, thereby helping to reduce the welding failure rate between the second pole column 52 and the second welding ring 54. At the same time, the peripheral side surface of the second assembly part 523a is flush with the peripheral side surface of the second assembly part 523b, so that the fitting position of the second welding ring body 541 and the second pole column 52 has no step structure, and interference fit between the second welding ring body 541 and the second pole column 52 is avoided, so that the false sealing state of the second welding ring 54 and the second pole column 52 is prevented, so as to avoid the product with abnormal sealing state from being detected when the energy storage device 100 is subjected to short circuit and withstand voltage test, thereby avoiding the unqualified products from flowing out, and helping to improve the production quality of the energy storage device 100.

[0095] In the embodiment, the second welding ring 54 further comprises a second avoiding gap 544. Specifically, the opening of the second avoiding gap 544 is located on the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20. The second avoiding gap 544 is recessed from the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20 to the direction away from the cover 20, and penetrates the peripheral side surface of the second welding ring body 541. The second avoiding gap 544 is arranged around the second fitting hole 543 and is spaced apart from the second fitting hole 543, and the second avoiding gap 544 avoids the second protrusion 12 of the lower plastic 10. With the above arrangement, on the one hand, the second protrusion 12 can be given space in the thickness direction of the end cover assembly 120, so as to prevent the second protrusion 12 from being broken due to being too thin when the second welding ring 54 and the second pole column 52 are crimped, so as to prevent the electrolyte in the energy storage device 100 from penetrating into the first welding ring 44 and the cover 20 through the gap between the second welding ring 54 and the second protrusion 12 of the lower plastic 10, improve the insulation performance between the second welding ring 54 and the cover 20, avoid short circuit problem in the end cover assembly 120, and help to improve the assembly reliability of the end cover assembly 120. On the other hand, the area of the crimping surface between the second welding ring 54 and the lower plastic 10 can be increased, so as to prolong the penetration path of the electrolyte, and further improve the sealing performance of the end cover assembly 120.

[0096] In addition, the second avoiding gap 544 comprises a second side wall surface 544a. The second side wall surface 544a is arranged around the circumferential side of the second pole post 52. Specifically, the second side wall surface 544a is arranged around the circumferential side of the second fixed part 523 of the second pole post 52. In the embodiment, the second side wall surface 544a is located between the surface of the second protrusion 22 of the cover 20 facing the second pole post 52 and the circumferential surface of the second pole post 52. Specifically, the second side wall surface 544a is located between the surface of the second protrusion 22 facing the second fixed part 523 and the circumferential surface of the second fixed part 523. With the arrangement, the second side wall surface 544a can be arranged in a staggered manner with the surface of the second protrusion 22 facing the second pole post 52.

[0097] Please refer to FIG. 4, FIG. 14 and FIG. 18. FIG. 18 is a structure diagram of the second sealing ring 53 in the second pole post unit 50 shown in FIG. 14, which is cut along K-K.

[0098] In the embodiment, the structure of the second sealing ring 53 is the same as that of the first sealing ring 43. The second sealing ring 53 is sleeved on the second assembly part 523a of the second pole post 52, and is clamped between the cover 20 and the lower plastic 10, and is clamped between the cover 20 and the second welding ring 54. The second sealing ring 53 can not only ensure the assembly stability between the second welding ring 54 and the cover 20, and between the lower plastic 10 and the cover 20, but also can avoid the direct contact and conduction between the second welding ring 54 and the cover 20, so as to realize the insulation between the second welding ring 54 and the cover 20.

[0099] Specifically, the second sealing ring 53 comprises a second sealing body 531, a second sealing flange 532 and a second protruding tooth 533. The second sealing flange 532 and the second protruding tooth 533 are fixedly connected to the second sealing body 531, and are located at opposite sides of the second sealing body 531, respectively. Specifically, the second sealing body 531 is sleeved on the second assembly part 523a of the second pole post 52, and is clamped between the groove bottom wall surface of the second assembly groove 207 of the cover 20 and the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20. The second sealing body 531 seals the gap between the groove bottom wall surface of the second assembly groove 207 and the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20.

[0100] The second sealing flange 532 is connected to the side of the second sealing body 531 away from the second assembly part 523a of the second pole post 52, and is clamped between the second protrusion 22 of the cover 20 and the second protruding block 12 of the lower plastic 10, and seals the gap between the second protruding block 12 and the second protrusion 22. It can be understood that, by arranging the second side wall surface 544a of the second welding ring 54 in a staggered manner with the surface of the second protrusion 22 facing the second pole post 52, the second sealing flange 532 can be provided with the maximum pressure bonding area, thereby helping to improve the sealing performance between the cover 20 and the lower plastic 10.

[0101] In the embodiment, the thickness of the second sealing flange 532 is less than the thickness of the second sealing body 531 along the thickness direction of the end cover assembly 120, and the compression amount of the second sealing flange 532 is less than the compression amount of the second sealing body 531. In the embodiment, the ratio of the initial thickness of the second sealing flange 532 to the distance between the surface of the lower plastic 10 facing the second protrusion 22 and the surface of the second protrusion 22 facing the lower plastic 10 is a2, and 1.08≤a2≤2.22. The ratio of the initial thickness of the second sealing body 531 to the distance between the bottom wall surface of the second assembly groove 207 and the surface of the second welding ring 54 facing the cover 20 is b2, and 1.31≤b2≤1.92. The “initial thickness of the second sealing flange 532” refers to the thickness of the second sealing flange 532 before compression, and the “initial thickness of the second sealing body 531” refers to the thickness of the second sealing body 531 before compression. With this arrangement, the compression amount of the second sealing flange 532 can be ensured to be less than the compression amount of the second sealing body 531, thereby preventing the second sealing flange 532 from affecting the overall sealing performance of the end cover assembly 120.

[0102] It should be noted that in actual production, the size and assembly tolerance of the components such as the lower plastic 10 and the cover 20 in the end cover assembly 120 need to be adjusted according to the requirements of the product, so as to control the compression amount of the second sealing flange 532 and the second sealing body 531 of the second sealing ring 53.

[0103] It can be understood that during the assembly of the end cover assembly 120, when the second welding ring 54 is welded with the second pole 52, the second welding ring 54 will extrude the lower plastic 10 and the second sealing ring 53, and by clamping the second sealing flange 532 of the second sealing ring 53 between the second protrusion 22 of the cover 20 and the second protrusion 12 of the lower plastic 10, the second sealing flange 532 is extruded and compressed, and seals the gap between the second protrusion 22 and the second protrusion 12, thereby achieving the sealing between the cover 20 and the lower plastic 10, preventing the electrolyte inside the energy storage device 100 from entering between the cover 20 and the second welding ring 54 through the gap between the second protrusion 22 of the cover 20 and the second protrusion 12 of the lower plastic 10, thereby avoiding the short circuit breakdown problem of the energy storage device 100 in short circuit and voltage test, preventing the energy storage device 100 from catching fire and explosion, and further helping to improve the safety and reliability of the energy storage device 100.

[0104] The second protrusion 533 is connected to one side of the second assembly part 523a of the second sealing body 531 facing the second pole 52, and abuts against the second assembly part 523a of the second pole 52, so that the peripheral surface of the second assembly part 523a of the second pole 52 is spaced apart from the second sealing body 531. For example, the second protrusion 533 has a plurality of second protrusions 533. The plurality of second protrusions 533 are spaced apart from each other.

[0105] In the embodiment, the second protrusion 533 is arranged on one side of the second sealing body 531 of the second sealing ring 53 facing the second pole 52, and abuts against the second pole 52, so that the second sealing flange 532 is spaced apart from the peripheral surface of the second pole 52 during compression of the second sealing ring 53, and the false sealing state caused by the second sealing body 531 of the second sealing ring 53 being in contact with the second pole 52 or the second upper plastic 51 after being compressed is avoided. The problem that the welding or other sealing of the end cover assembly 120 is not easy to detect when an abnormality occurs is solved, so that the outflow rate of defective products is reduced, and the production quality of the energy storage device 100 is improved.

[0106] In the embodiment, the second sealing ring 53 further includes a second central surface 53a. The second central surface 53a is perpendicular to the thickness direction of the second sealing ring 53, and passes through the second sealing body 531, the second sealing flange 532 and the second protrusion 533. Along the thickness direction of the second sealing ring 53, the second sealing ring 53 is mirror-symmetric about the second central surface 53a. With this arrangement, during assembly of the end cover assembly 120, the front and back positions of the second sealing ring 53 do not need to be considered, which helps to reduce the assembly difficulty of the second sealing ring 53 in the end cover assembly 120, and thus facilitates to speed up the production rhythm of the end cover assembly 120 and improve the production efficiency.

[0107] In addition, when the second sealing ring 53 is assembled with the lower plastic 10, the plurality of second guide blocks 14 of the lower plastic 10 are located on the side of the second sealing flange 532 away from the second sealing body 531. With this arrangement, the assembly position of the second sealing ring 53 in the end cover assembly 120 can be limited, and the compression space of the second sealing ring 53 can be ensured when the second sealing ring 53 is compressed.

[0108] Please refer to FIG. 3 and FIG. 4 again. The end cover assembly 120 further comprises a top patch 70. The top patch 70 is a rectangular sheet in an example. The top patch 70 is mounted on the first surface 20a of the cover body 20, and covers the liquid injection hole 202 and shields at least part of the protruding portion 415. The top patch 70 can play an insulation role. Specifically, the top patch 70 is provided with a first avoiding hole 701, a second avoiding hole 702, and a third avoiding hole 703. The first avoiding hole 701, the second avoiding hole 702, and the third avoiding hole 703 all penetrate the top patch 70 along the thickness direction of the top patch 70, and are arranged at intervals. Along the length direction of the top patch 70, the first avoiding hole 701 and the second avoiding hole 702 are respectively located on the opposite sides of the third avoiding hole 703. Among them, the first avoiding hole 701 avoids the first upper plastic 41, and the second avoiding hole 702 avoids the second upper plastic 51. When the energy storage device 100 is in thermal runaway, the third avoiding hole 703 can avoid the explosion-proof valve 30.

[0109] It can be understood that by arranging the top patch 70 and shielding at least part of the protruding portion 415 of the first upper plastic 41 by the top patch 70, the crystallization of the electrolyte from the assembly gap between the first upper plastic 41 and the cover body 20 can be prevented, thereby helping to improve the appearance yield of the energy storage device 100 and ensuring that the appearance of the energy storage device 100 is relatively neat. In other embodiments, when the second upper plastic 51 is provided with the protruding portion 415 described above, the protruding portion 415 of the second upper plastic 51 is mounted in the mounting groove 205 arranged around the second assembly hole 204. At this time, the top patch 70 can also cover the assembly gap between the protruding portion 415 of the second upper plastic 51 and the cover body 20, prevent the crystallization of the electrolyte from the assembly gap between the second upper plastic 51 and the cover body 20, thereby also helping to improve the appearance yield of the energy storage device 100 and ensuring that the appearance of the energy storage device 100 is relatively neat.

[0110] The present application also provides a power utilization device, which comprises the energy storage device 100 described above, and the energy storage device 100 supplies power to the power utilization device. The power utilization device can be a new energy vehicle, a power storage station, a server, or other devices that need power.

[0111] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application; the embodiments of the present application and the features in the embodiments can be combined with each other without conflict. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An end cap assembly for an energy storage device, comprising: The end cover assembly comprises a lower plastic, a cover, a pole, a sealing ring and a welding ring. The lower plastic is provided with a through hole penetrating the lower plastic along the thickness direction of the lower plastic. The cover is installed on one side of the lower plastic along the thickness direction of the lower plastic. The cover is provided with an assembly hole and an assembly groove. The assembly hole penetrates the cover along the thickness direction of the cover and communicates with the through hole. The opening of the assembly groove is located on the surface of the cover facing the lower plastic. The assembly groove is arranged around the assembly hole and communicates with the assembly hole. The cover is further provided with a convex block. The convex block is arranged on the groove bottom wall surface of the assembly groove. The convex block is spaced apart from and opposite to the lower plastic along the thickness direction of the end cover assembly. The pole is arranged in the through hole and the assembly hole. The welding ring is located on the side of the lower plastic away from the cover and is sleeved on the pole. The sealing ring is sleeved on the pole. The sealing ring comprises a sealing body and a sealing flange. The sealing body is sleeved on the pole and is clamped between the groove bottom wall surface of the assembly groove and the surface of the welding ring facing the cover. The sealing flange is connected to the side of the sealing body away from the pole, is arranged around the circumferential side of the sealing body and is clamped between the convex block and the lower plastic.

2. The end cap assembly of claim 1, wherein, The lower plastic is further provided with a convex block. The convex block is connected to the hole wall surface of the through hole and is arranged around the center of the through hole. The convex block is spaced apart from and opposite to the convex block along the thickness direction of the end cover assembly. The sealing flange is clamped between the convex block and the convex block.

3. An end cap assembly according to claim 1 or 2, wherein, The thickness of the sealing flange is smaller than the thickness of the sealing body along the thickness direction of the end cover assembly. The compression amount of the sealing flange is smaller than the compression amount of the sealing body.

4. The end cap assembly of claim 3, wherein, The ratio a between the initial thickness of the sealing flange and the distance between the surface of the lower plastic facing the convex block and the surface of the convex block facing the lower plastic is 1.08≤a≤2.

22. The ratio b between the initial thickness of the sealing body and the distance between the groove bottom wall surface of the assembly groove and the surface of the welding ring facing the cover is 1.31≤b≤1.

92.

5. The end cap assembly of claim 2, wherein, The convex block and the convex block are annular. The sealing ring has a center surface perpendicular to the thickness direction of the sealing ring. The sealing ring is mirror symmetric about the center surface along the thickness direction of the sealing ring.

6. The end cap assembly of claim 1, wherein, The sealing ring further comprises a convex tooth. The convex tooth is connected to the side of the sealing body facing the pole and abuts against the pole.

7. The end cap assembly of claim 6, wherein, The convex tooth has a plurality of convex teeth. The plurality of convex teeth are spaced apart around the pole.

8. The end cap assembly of claim 2, wherein, The welding ring is provided with an avoiding notch. The opening of the avoiding notch is located on the surface of the welding ring facing the cover. The avoiding notch penetrates the circumferential surface of the welding ring. The avoiding notch avoids the convex block.

9. The end cap assembly of claim 8, wherein, The avoiding notch comprises a side wall surface. The side wall surface is arranged around the circumferential side of the pole and is located between the surface of the convex block facing the pole and the circumferential surface of the pole.

10. The end cap assembly of claim 1, wherein, The lower plastic includes a first surface facing the cover, the first surface is provided with a guide block, the guide block is arranged around the circumferential side of the through hole, is installed in the assembly groove, and is located on the side of the sealing flange away from the sealing body, the guide block includes a guide surface located on the side of the guide block away from the through hole, the guide surface includes a first end close to the first surface and a second end arranged away from the first end, and the distance between the guide surface and the first surface gradually increases from the first end to the second end.

11. The end cap assembly of claim 1, wherein, The cover is provided with a mounting groove, the opening of the mounting groove is located on the surface of the cover away from the lower plastic, the mounting groove is arranged around the assembly hole, and is arranged in a spaced manner with the assembly hole; The end cover assembly further includes an upper plastic, the upper plastic includes a main body part and a protruding part, the main body part is sleeved on the pole, and is connected between the pole and the cover, the protruding part is connected to the side of the main body part facing the cover, and fills the mounting groove.

12. The end cap assembly of claim 11, wherein, The circumferential surface of the protruding part is protruded relative to the circumferential surface of the first main body part.

13. The end cap assembly of claim 12, wherein, The end cover assembly further includes a top piece, the top piece is installed on the side of the cover away from the lower plastic, and at least partially covers the protruding part.

14. The end cap assembly of any one of claims 11-13, wherein, The pole includes a flange part, the flange part is located on the side of the main body part away from the cover; The main body part includes a connecting surface away from the cover, the connecting surface is arranged around the circumferential surface of the flange part, the connecting surface includes a first side close to the flange part and a second side arranged away from the first side, and the distance between the connecting surface and the surface of the cover facing the main body part gradually decreases from the first side to the second side.

15. The end cap assembly of claim 14, wherein, The connecting surface is an arc surface.

16. The end cap assembly of claim 14, wherein, The first side is arranged in a spaced manner with the circumferential surface of the flange part.

17. An energy storage device, characterized by The end cover assembly as claimed in any one of claims 1 to 16 is installed on the shell, and seals the opening of the shell.

18. An electrical device, characterized by The energy storage device as claimed in claim 17 is used to supply power to the electric device.

Images